A taxonomic revision of the Asian keelback snakes, genus Amphiesma (Serpentes: Colubridae: Natricinae), with description of a new species.

The Asian keelback snakes (genus Amphiesma) are a widely distributed group of Old World natricines, inhabiting a variety of niches and exhibiting significant morphological variation. Recent molecular phylogenies suggest that this genus is not monophyletic, and that additional cryptic diversity is also likely present. We conducted a phylogenetic analysis of the group based on 3162 bp of one mitochondrial gene (Cyt. b) and three nuclear genes (C-mos, Rag1, NT3), sampling 18 species in addition to those sequenced in previous works. All analyses consistently show that Amphiesma consists of three distinct, monophyletic lineages with strong support. We divide Amphiesma into three genera, Amphiesma, Hebius, and Herpetoreas. The genus Amphiesma is monotypic, Herpetoreas contains three species, and Hebius comprises the remaining 39 species. On the basis of a combination of molecular analyses and external morphological comparisons, we describe a new species in the Herpetoreas group from China as H. burbrinki sp. nov. Several other species are shown to be non-monophyletic or contain significant levels of intraspecific genetic diversity. Another Old World natricine genera, Xenochrophis is also found to be non-monophyletic. Our results indicate that further taxonomic revisions are needed in Natricinae, at multiple levels. 

Transport of intranasally instilled fine Fe2O3 particles into the brain: micro-distribution, chemical states, and histopathological observation.

It has been demonstrated that inhaled fine (d < 2.5 microm) and ultrafine (d < 100 nm) particles produce more severe toxicity than coarse particles. Some recent data support the concept that the central nervous system (CNS) may be a target for the inhaled fine particulates. This work describes initial observation of the transport of intranasally instilled fine ferric oxide (Fe2O3) particles in animal brain. The iron micro-distribution and chemical state in the mice olfactory bulb and brain stem on day 14 after intranasal instillation of fine Fe2O3 particle (280 +/- 80 nm) suspension at a single dose of 40 mg/kg body weight were analyzed by synchrotron radiation x-ray fluorescence and x-ray absorption near-edge structure (XANES). The micro-distribution map of iron in the olfactory bulb and brain stem shows an obvious increase of Fe contents in the olfactory nerve and the trigeminus of brain stem, suggesting that Fe2O3 particles were possibly transported via uptake by sensory nerve endings of the olfactory nerve and trigeminus. The XANES results indicate that the ratios of Fe (III)/Fe (II) were increased in the olfactory bulb and brain stem. The further histopathological observation showed that the neuron fatty degeneration occurred in the CA3 area of hippocampus. Such results imply an adverse impact of inhalation of fine Fe2O3 particles on CNS.